The employment of many large scale electronic computer systems for performing a wide variety of computational and logical manipulations on sets of data has led to a recognition that a voice response to human users is a desirable feature. Many electronic systems research and development organizations are attempting to develop a practical system for synthesizing speech by means of a voice waveform synthesizer. Because of the synthesis techniques and compilation systems used, voice synthesizers have either an undesirably small vocabulary, or poor sound quality, or are so costly to build and operate that they are impractical for many desired commercial applications.
For instance, hardware has been developed for synthesizing speech in real time by concatenating formant data. Although such hardware can produce high quality speech, relatively complex and expensive arrangements of equipment are required. Electron. Commun. Japan, 52-C, 126-134, (1969); IEEE Trans. on Comm. Tech., Vol. COM-19, No. 6, 1016-1020, (Dec. 1971); U.S. Pat. No. 3,828,132; and BYTE, No. 12, 16-24 and 26-33, (Aug. 1976).
Speech also has been synthesized by linear prediction of the speech waveform. This method of speech generation produces higher quality speech than the aforementioned arrangements but requires more memory as well as relatively complex and expensive equipment arrangement. Acoust. Soc. of Amer., 50, 637-655, (1971).
There is a need, therefore, for a simple voice synthesizer which inexpensively produces a relatively large vocabulary of high quality sounds.
It is an object of the invention to develop a voice waveform synthesizer.
It is still another object to provide a voice synthesizer which produces acceptably good quality sounds.
It is a further object to develop an inexpensive voice synthesizer having a relatively large vocabulary.
It is a still further object to advantageously employ a microprocessor in a good quality voice synthesizer.